1. Field of the Invention
The present invention relates to a liquid crystal display device, and more particularly, to a liquid crystal display device that can maintain a uniform cell gap and prevent light leakage and a manufacturing method thereof.
2. Description of the Related Art
A cathode ray tube (CRT) device is advantageous with regard to performance and price, but is disadvantageous with regard to size and portability. In contrast, a liquid crystal display (LCD) device is advantageous with regard to size, weight, and power consumption, and is future replacement for replacing the CRT devices. In addition, the LCD device is commonly used as a display for most information processing devices.
FIG. 1 is a schematic perspective view of a LCD manufacturing process according to the related art. In FIG. 1, a plurality of pixels are formed in a matrix configuration through an array substrate manufacturing process, and a color filter layer is formed through a color filter manufacturing process. Then, the array substrate and the color filter layer are combined together. During the combining process, spacers are dispersed on the color filter for maintaining a uniform cell gap, and a seal line is printed on the array substrate for maintaining a cell gap and encapsulating liquid crystal material between the array substrate and the color filter layer. After the spacer dispersing process and the seal printing process, the surface of the color filter upon which the spacers are dispersed is disposed to face the surface of the array substrate's upon which the seal line is printed on, and then the two substrates are combined together by exposure to heat, pressure, and ultraviolet (UV) rays. Thereafter, a cell process for cutting the combined substrates into a size of a liquid crystal panel is executed, and a liquid crystal injection process for injecting and encapsulating the liquid crystal is performed. Although not shown in FIG. 1, a module process for assembling a gate PCD and a data PCD is performed after the liquid crystal injection process.
FIG. 2 is a schematic perspective view of a process for dispersing spacers on a color filter according to the related art. In FIG. 2, ink containing spacers are dispersed on a color filter 10 using an inkjet device. In the inkjet device, a supply unit 15 for supplying ink containing spacers to an inkjet head 20 is connected to the inkjet head 20, and the inkjet head 20 has a plurality of spray nozzles 22 disposed therein. In addition, the spray nozzles 22 are connected to a control unit 12 for adjusting a spray operation.
The spacers are dispersed by the inkjet device using the following method. First, when ink containing spacers are supplied from the supply unit 15 to the inkjet head 20, the inkjet head 20 sprays the supplied ink on the color filter 10 through the spray nozzles 22. At this time, ink droplets containing spacers are sprayed through the spray nozzles 22 on the color filter 10 at desired positions according to a control signal supplied from the control unit 12.
FIG. 3 is a plan view of spacers dispersed on a color filter according to the related art. In FIG. 3, when ink droplets mixed with spacers (indicated by black points) are dispersed using the inkjet technique, the ink droplets can be dispersed at approximately-desired positions on a color filter. Accordingly, the sprayed spacers are connected with an array substrate to maintain a cell gap between two substrates. However, the spacers are disposed not only on a non-display region (a black matrix) but also on a display region (a color filter layer) of the color filter. That is, the spacers are non-uniformly dispersed on R/G/B color filter layers and a black matrix region.
When the spacers are disposed on the color filter layer (the display region), an aperture ratio of a pixel region is deteriorated and light is leaked after it is dispersed by the spacers disposed on the display region. The spacers can be disposed on the display region because their positions are varied as an ink droplet containing them is dried.
FIG. 4 is a plan view of exemplary spacer positions after an ink droplet mixed with the spacers is dried according to the present invention. In FIG. 4, when an ink droplet containing spacers is dropped onto the color filter, only the spacers remaining on the color filter after the ink droplet dry. At this time, the spacers are gathered either around the center of the ink droplet or at the circumference thereof. Accordingly, this causes a non-uniform dispersion of the spacers. Particularly, since the ink droplet is 60 μM or larger in diameter, the spacers are apt to be disposed at the R/G/G color filter layers, that is, at undesirable positions.